This invention relates to a protective bushing adapted for use in a cut end of a BX armored cable or the like.
When a piece of BX cable, of normal configuration is cut, as by means of a hand or power cutting tool, on a path parallel to the longitudinal axis of the cable, the cut end presents inner and outer, helically disposed, rather sharp edges adjacent to the straight cut edge. A cable cutter adapted to make such a cut, which is clean and has no ragged edges, is disclosed in Ducret U.S. Pat. No. 3,851,387, which tool was introduced in 1973 under the trademark "ROTO-SPLIT" and has since won wide acceptance.
A BX cable, in normal use, contains and protects one or more insulated wires which protrude from the cut end of the cable (however the cut may have been made) for connection to any suitable electric device, appliances, tools or circuit elements. Each insulated wire exiting from the cut end of the cable and led in a direction which departs from the cable axis necessarily has its insulation pressed against the inner edge of the cut end of the cable, and damage to the insulation frequently ensues as a result of friction and/or pressure at the point of contact.
Installation of insulating bushings between the wires and the armor was required when it was found that chafing could occur and could be a potential cause of "shorts". Simple, known, bushings, identified as "Red Heads", are not designed to match the spiral of the BX in a parallel cut end. They are made of thin plastic material and many times they do not cover the full internal circumference of the armor. This condition is potentially dangerous since the wires could still come in contact with a sharp edge of the armor and possibly damage the insulation.
It is accordingly an object of the present invention to provide a bushing of durable plastic material (or the like) which is so positioned in the cut end of the cable that all sharp edges which might damage the insulation on the wire or wires, are covered and prevented from contacting any insulation surface.
It is a further object of the invention to provide a safe insulating bushing with a construction intended to fill completely the gap between the BX armor previously cut with the "Roto-Split" cutter (hereinafter referred to as "parallel cut") and a theoretical square cut end of the cable. The new bushing, preferably, has an overlapping portion which can be squeezed to fit different internal diameters. This feature provides full insulation over the complete circumference.
The bushing of this invention is of molded insulating material, solid or split and overlapped, formed as a sleeve which shields the wires in a BX cable from contact with the cable armor at or near a cut end of such cable, particularly a cable end which has been cut in a plane parallel to the axis of the cable.